Related papers: Gravitational Radiation from String Cosmology
Gravitational waves (GWs) have a great potential to probe cosmology. We review early universe sources that can lead to cosmological backgrounds of GWs. We begin by presenting definitions of GWs in flat space-time and in a cosmological…
It is shown that the expected amplitudes and specific correlation properties of the relic (squeezed) gravitational wave background may allow the registration of the relic gravitational waves by the first generation of sensitive gravity-wave…
Stochastic gravitational wave background from the early Universe has a cut-off frequency close to 100 MHz, due to the horizon of the inflationary phase. To detect gravitational waves at such frequencies, resonant electromagnetic cavities…
We estimate the stochastic gravitational wave spectrum emitted from a network of cosmic strings in which the latter are effectively stable against breaking by monopole pair creation. The monopoles are produced at a higher scale from an…
Recently, multiple pulsar timing array collaborations have presented compelling evidence for a stochastic signal at nanohertz frequencies, potentially originating from cosmic strings. Cosmic strings are linear topological defects that can…
We investigate the ability of the Laser Interferometer Space Antenna (LISA) to detect a stochastic gravitational-wave background (GWB) produced by cosmic strings, and to subsequently estimate the string tension $G\mu$ in the presence of…
Stochastic gravitational wave background produced by a stationary coalescing population of binary neutron stars in the Galaxy is calculated. This background is found to constitute a confusion limit within the LISA frequency band up to a…
Stochastic gravitational waves (GW) associated with unresolved astrophysical sources at frequency bands of the ongoing GW interferometers LIGO/VIRGO and LISA are studied. We show that GW noise from rotating galactic neutron stars with low…
We discuss the gravitational wave background generated by primordial density perturbations evolving during the radiation era. At second-order in a perturbative expansion, density fluctuations produce gravitational waves. We calculate the…
If cosmic strings are formed in the early universe, their associated loops emit gravitational waves during the whole cosmic history and contribute to the stochastic gravitational wave background at all frequencies. We provide a new estimate…
We calculate the density and gravitational wave spectrums generated in a version of string cosmology termed pre-big bang scenario. The large scale structures are originated from quantum fluctuations of the metric and dilaton field during a…
In the context of the pre-Big Bang scenario of string cosmology, we propose a modified equation for the evolution of the tensor perturbations, which includes the full contribution of possible higher-order curvature and coupling corrections…
It is shown that coupling system between fractal membranes and a Gaussian beam passing through a static magnetic field has strong selection capability for the stochastic relic gravitational wave background. The relic GW components…
We discuss the potential cosmological role of gravitational wave astronomy as a probe of the very early universe. The next generation of detectors - now in production - may be able to observe a stochastic background of gravitational waves…
In the near future we will witness the coming to a full operational regime of laser interferometers and resonant mass detectors of spherical shape. In this work we study the sensitivity of pairs of such gravitational wave detectors to a…
String gas cosmology is a string theory-based approach to early universe cosmology which is based on making use of robust features of string theory such as the existence of new states and new symmetries. A first goal of string gas cosmology…
We review the status of String Gas Cosmology after the 2015 Planck data release. String gas cosmology predicts an almost scale-invariant spectrum of cosmological perturbations with a slight red tilt, like the simplest inflationary models.…
Early dark energy that relieves Hubble tension leaves a fingerprint in the primordial stochastic gravitational wave (GW) background that originates from cosmic string network. The signal is not only detectable with future planned GW…
A stochastic background of relic gravitational waves is achieved by the so called adiabatically-amplified zero-point fluctuations process derived from early inflation. In principle, it provides a distinctive spectrum of relic gravitational…
Correlated red noise recently reported from pulsar timing observations may be an indication of stochastic gravitational waves emitted by cosmic strings that formed during a primordial phase transition near the Grand Unification energy…